How to use "--" as an argument in python argparser

Question

I have the following python code set up, in which the program would return "something" whenever the user pass -- as an argument:

#script.py

import argparse

parser = argparse.ArgumentParser()

parser.add_argument(
    "--",
    help="Prints something",
    action="store_true",
    dest="print_something",
)

args = parser.parse_args()

if args.print_something:
    print("something")

The output is as follows:

$ python .\script.py --

usage: script.py [-h] [--]
playground.py: error: unrecognized arguments: --

Argparse is not able to recognise the -- argument.

I tried using escape sequences, like putting -\-\- under parser.add_argument(, yet the program is not behaving the way it should.

There is, of course, a workaround using sys.arg, which goes something like:

import sys

if "--" in sys.argv:
    print("something")

But the above approach is impractical for projects with alot of arguments -- especially for those containing both functional and positional argument.

Therefore, is there anyway to parse the -- argument using argparser?

Answer 1

Not sure if this is what you mean, but using this logic you can detect -- and process other using something like this:

import argparse

parser = argparse.ArgumentParser()

# Define a positional argument to capture `--` and any arguments after it
parser.add_argument(
    'args',
    nargs=argparse.REMAINDER,
    help="Arguments after --"
)

parsed_args = parser.parse_args()

# Check if `--` is in the arguments
if '--' in parsed_args.args:
    print("Found -- in arguments")
    # You can process the arguments after `--` here
    remaining_args = parsed_args.args[parsed_args.args.index('--') + 1:]
    # process other arguments here
    print("Arguments after --:", remaining_args)
else:
    print("No -- found in arguments")

So to answer your question: yes, but its quite niche.